274 GEORGE HOGGAX ON A 



failed in convincing you, or at all events in impressing upon you 

 tlie necessity of so using it. 



As connected with the sawing side of the machine I may note 

 that the saw called the " Pearl saw" is the best adapted for the 

 machine. This I have found, as the result of experience, after 

 having tried about a score of different sorts and sizes, some of 

 them much larger and coarser, while others were only about one 

 quarter the size of this one. The larger saws, however, left too 

 coarse a surface on the section, and were very apt to break down 

 thin sections ; while the very fine saws were apt to bend, and thus 

 go out of the parallel plane. As a rule, choose those with the 

 finest teeth, the thinest blade, and as broad as possible — say about 

 one-eighth of an inch broad. These blades only cost 6d. a bundle 

 of one dozen, so that one need not be tempted to use a saw too 

 long on account of its costliness. Put also a thin piece of cork or 

 wood under the material to be cut ; this prevents the saw from 

 cutting the brass table, and it also keeps the article to be cut 

 steadier while being sawn. A little bit of brown paper between 

 the screw point and the article has a good effect in the same way. 



Put also a little oil on the frame of the saw, so that it may work 

 easily in the upper guides, but do not oil the saw-blade, or the 

 section will be dirtied thereby. It will be seen that the bases of 

 both upper and lower saw guides have a slit cut in them, and are 

 tightened with a thumbscrew. This enables us to regulate the 

 distance according to the thickness of the saw ; and we are also 

 enabled to remove them, when necessary, without altogether re- 

 moving the thumbscrew. In addition, the upper ones have the 

 upper edges of the base levelled, so as to fit into a corresponding 

 levelled groove on the top of the frame, so that by keeping it firm 

 in position all shaking when sawing may be avoided. The bases 

 of the lower ones are similarly guided by the inside edge lying 

 against the edge of the moving table, which projects above the 

 level of the plate for this purpose. 



The contrivance for fixing the article to be cut on the table con- 

 sists of an arched piece of metal (c), through the centre of which 

 the compressing screw passes, and having its extremities formed 

 like the f* headed bolts used in machine shops for bolting articles 

 on to a moving table. These two extremities move in two parallel 

 grooves along the table, and thus enable us to fix the article to be 

 cut at any part of the table, and also to use two compressors at 



